docs: def bend_miter_Miller(Di, angle, Re, roughness=0.0, L_unimpeded=None):
      r'''Calculates the loss coefficient for a single miter bend according to 
      Miller [1]_. This is a sophisticated model which uses corrections for
      pipe roughness, the length of the pipe downstream before another 
      interruption, and a correction for Reynolds number. It interpolates several
      times using several corrections graphs in [1]_.
      
      Parameters
      ----------
      Di : float
          Inside diameter of pipe, [m]
      angle : float
          Angle of miter bend, [degrees]
      Re : float
          Reynolds number of the pipe (no specification if inlet or outlet
          properties should be used), [m]
      roughness : float, optional
          Roughness of bend wall, [m]   
      L_unimpeded : float, optional
          The length of unimpeded pipe without any fittings, instrumentation,
          or flow disturbances downstream (assumed 20 diameters if not 
          specified), [m]
  
      Returns
      -------
      K : float
          Loss coefficient [-]
  
      Notes
      -----    
      Note the loss coefficient includes the surface friction of the pipe as if
      it was straight.
     
      Examples
      --------
      >>> bend_miter_Miller(Di=.6, angle=90, Re=2e6, roughness=2e-5, 
      ... L_unimpeded=30*.6)
      1.1921574594947668
      
      References
      ----------
      .. [1] Miller, Donald S. Internal Flow Systems: Design and Performance
         Prediction. Gulf Publishing Company, 1990.
      '''
      if L_unimpeded is None:
          L_unimpeded = 20.0*Di
      if angle > 120:
          angle = 120.0
      
      Kb = horner(bend_miter_Miller_coeffs, 1.0/60.0*(angle-60.0))
      
      C_o =  Miller_bend_unimpeded_correction(Kb=Kb, Di=Di, L_unimpeded=L_unimpeded)
      C_roughness = Miller_bend_roughness_correction(Re=Re, Di=Di, 
                                                     roughness=roughness)
      Re_C_Re = min(max(Re, 1E4), 1E8)
      C_Re_1 = bend_rounded_Miller_C_Re(Re_C_Re, 1.0) if Re_C_Re < 207956.58904584477 else 1.0
      C_Re = Kb/(Kb - 0.2*C_Re_1 + 0.2)
      if C_Re > 2.2 or C_Re < 0:
          C_Re = 2.2
      return Kb*C_Re*C_roughness*C_o